The density of a body is defined as the ratio of the mass m, and the volume V occupied by the body.
ρ = m/V
ρ → Density
m → mass of the body.
V → Volume of the body.
In this case we have a density:
ρ = 20.0 g/31.0 ml = 0.645 g/ml
It means you should check your calculations. Maybe the equation used is not correct.
density is a ratio of mass to volume,
so density = mass/volume = 20/31 gm/ml = 0.645 gm/ml
Given mass=20.0 g)
=0.645(approx round off)
HOPE IT HELPS!!